[Plugin] ShadowProjector

Re: [Plugin] ShadowProjector

Postby TIG » Fri Jul 12, 2019 12:21 pm

I little more in depth analysis...

The model has not been Geo-located - you must do this in the Model Info settings.
Otherwise the shadow results will not be accurate - they vary by geographical-location, date and time.
Currently it has the template's default of Boulder (CO) USA, 40.01...N 105.28...W
Which I guess is NOT what you want ??

Once that's been resolved it'd be a good idea to set up some scene tabs for different dates/times - see below***...

The next thing you need to establish is the building's real orientation.
The axes have been changed to be square to the building [useful for modeling], but if you reset them to the model axes the building is at an angle in plan.
The sun will cast shadows according to the model-axes, irrespective of the current axes.
You can also get a tool from the EWH to reset 'North', thus changing the shadows without affecting the building's drawn layout - however, I don't think this is needed in your case ?

Next I suggest you edit the glass material ["VITRAGE"] in the model's materials so it is not transparent [i.e. 100% opaque] - that way it'll accept shadows, making it much easier for you to see which of the windows need analyzing.
There's no need to calculate those windows which are fully shaded - only those in the sun will get also some shading from their frames and reveals, and the timber deck/roof.
This will save save wasted effort.

In passing - I also notice that the topmost floors' windows have no 'brise-soleils' above them in the center parts, but in the outermost wings they do - which is illogical - you either need to shade windows or you don't - a 'half-way-house' is either wasting the client's money or not giving him a properly worked out design. Remember that brise-soleils are not 'aesthetic' they have a function !

***You also need to establish the time of day and the month needed for these shadow studies.
Usually it is around noon at the two solstices and also at an equinox, and possibly earlier and/or later in the day depending on the requirements.

Are you wanting to find the % shaded ?
Or are you looking to find the % getting sunlight ?*

Because of the complex geometry of the slatted parts, to be honest, it'd probably be far simpler for you to overdraw faces onto the glass around the shaded areas [or the lit areas*], the get the area[s] of selected face[s] from Entity Info...

I note that [using the more-than-likely 'wrong' Geo-location] at noon in June [and March] only the top few windows get any light at all - the rest are shaded 100%.
Also because the form of the building several windows/shadows sets are repeated, so there's no need to process every one of them ?
An noon in December they will all get some light, but again there are many 'repeats' of those sets.
Tip: switch off snapping in Model Info > Units when over-drawing...

If you go down the manual drawing route, then exploding everything could also be counter-productive...
It'd be easier to draw over components/groups !

PS: I also note that you have raw geometry on various layers - probably because you exploded several component/groups etc.
Raw geometry [edges and faces] should be assigned to Layer0: otherwise madness can result !
To revert them use a tool like my LayerWatcher, or simply delete all of the confusing layers in the Layer Manager and let everything revert to the default [Layer0]...

PPS: Here's a screenshot of the left-one done with ShadowProjector and the right-one drawn manually+EntityInfo+Calc+3dText [somewhat faster!].
Note that the actual pane's area 1.65m² was rounded to 1 d.p. by SP as 1.7m².
I also happened to use a different font for my 3dText...
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Re: [Plugin] ShadowProjector

Postby VERSEAU44 » Fri Jul 12, 2019 4:18 pm


Many thanks for your detailed answer

I had planned to orient my model: the file was sent so that you realize the complexity of modeling and understanding why SP crashes

In fatc, I realize a PHPP (PassivHaus : energetic standard for buildings) study which asks for EACH bay leaf a correction factor (one for winter and one for summer) which indicates how much of the solar radiation hits the window surface relative to the radiation that would occur without this shading element (hence the complement of the % SP).
I thought I would take the average between the most favorable and the worst of each period (winter / summer)

The many small shadows created by the slatted handrails are too complicated to manually calculate this % : taht's the reason I pass through SketchUP + SP !

The rounding of 1.65 to 1.7m ² is against a real problem for the precision of the result : can SP be more precise ?

I do not understand when you explain : "it should probably be simpler for you to get over the surfaces of the shaded areas [or the bed areas *], get the area [s] of selected face [s] from Entity Info"
The result will not be the same as the % given by ShadowProject ? Why do it if SP gives it to me directly, knowing that the model is too complex to draw manually ?

Sorry, I'm trying to understand at best ...

Thanks a lot for your help to a beginner (but probably your answer can help anothers who wonder how SP can answer to ...)


Re: [Plugin] ShadowProjector

Postby TIG » Fri Jul 12, 2019 5:46 pm

Before you proceed...

Get your model Geo-located properly.

Set up your Scene-tabs for the relevant times/dates.

Set the glass material to be 100% opaque - so you can see the shadows.

You only need to consider windows with some light falling on them.

Next, you can use SP on individual panes of glass to get % shading.
However, unless there are lots of panes with different 'slat' shadows, then a manual fix would be quicker/safer...
Many windows' shading repeats so you do not need to do every one...

Note my comment about simplifying your layers, so all geometry has Layer0...

If I understand you correctly, you need to do two time/date studies [with some 'averaging?] - if you need 'lit' versus 'shaded' %s then a manual method might well be quicker ?
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Re: [Plugin] ShadowProjector

Postby VERSEAU44 » Fri Jul 12, 2019 6:18 pm

Thanks for all TIG : I'll try ...

What I still do not understand is that you stay on a manual method (quicker according to you) BUT, as already said, the many small shadows created by the slatted handrails are too complicated to calculate this % by drawing manually : that's the reason I use SketchUp + SP !
Is there something that escapes me ?

Last question : how to take into account diffuse radiation ? Because it can count for more than 50% of total solar radiation in Central Europe, and up to 100% for surfaces in the North !
Do SU and SP take this into account ?

Kind Regards


Re: [Plugin] ShadowProjector

Postby TIG » Fri Jul 12, 2019 7:09 pm

Last question first...
No diffuse radiation is taken into account.
It's a simple shaded/lit split.
It's not a complex app !
It's a free plugin !

Can you show me a screenshot of a window with 'slatted' shadows.
You must use the correct Geo-location and date/time.
And an opaque glass material.

No there is need to do a SP.

I think that if you look at it in detail, then many similar windows will be fully-shaded or shared 'repeated shading'...
So even a manually drawn solution could be done quite quickly.

In fact, much of the time used up discussing this could have been used 'doing' it !

With a proper brief, covering a proper Geo-location, real dates/times etc, then I could probably do this for you...
So perhaps a simple example is needed... followed by PMs ??
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Re: [Plugin] ShadowProjector

Postby Philicious89 » Wed Apr 29, 2020 7:08 pm

How can I install it on Mac?


Re: [Plugin] ShadowProjector

Postby TIG » Thu Apr 30, 2020 6:40 pm

The same way you install any other Extensions downloaded as RBZ files. :shock:

Download it and save the RBZ somewhere logical - like your Downloads folder.
Within SketchUp open the 'Extension Manager'.
In its dialog use the 'Install Extension' re-button.
Find the RBZ and it'll be auto-installed into the correct folders etc.
When it finishes use the tool as outlined in its usage guidance notes at the start of this post, or in the PluginStore's 'More Info' link...
Quick-tip - Tools > ShadowProjector > submenu items...
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